What are the common misunderstandings or misconceptions about using microtime() for measuring script performance in PHP?

One common misunderstanding is that using microtime() directly may not provide accurate results due to system overhead and other factors. To accurately measure script performance, it's recommended to use the microtime(true) function, which returns a float value representing the current time in microseconds.

$start_time = microtime(true);

// Code to measure performance

$end_time = microtime(true);
$execution_time = $end_time - $start_time;

echo "Script execution time: $execution_time seconds";